Maybe my point didn't come across as intended, however, I strongly disagree with any notion of defending this way of spell stacking as being derived from meta info. As pointed out by Bloodless earlier. Unless you are present to watch the spells being cast, it is not visually clear for some of the spells, at least. The defence to me is really absurd. I'm thinking from a PvP standpoint which is where this would mainly cause issues. There isn't a scenario where a complaint isn't raised when somebody's PC gets immediately badly impaired because they walked into a spell not knowing that there was an additional 19 of the same spell hidden within it. Probably less than half that amount from a warmage.
And yes, if a warlock requires this to be "viable" is a thing, then warlock needs looking at, or the thought of needing to be able to solo everything as a caster needs to be quashed.